Suppose Erie Textiles Can Dispose of Its Waste "For Free

Multiple Choice

Suppose Erie Textiles can dispose of its waste "for free" by dumping it into a nearby river. While the firm benefits from dumping waste into the river, the waste reduces fish and bird reproduction. This causes damage to local fishermen and bird watchers. At a cost, Erie Textiles can filter out the toxins, in which case local fishermen and bird watchers will not suffer any damage. The relevant gains and losses (in thousands of dollars) for the three parties are listed below. $$\begin{array} { | l | c | c | } \hline & \text { With Filter } & \text { Without Filter } \\\hline \text { Gains to Erie } & \$ 200 & \$ 400 \\\hline \text { Fisherman } & \$ 180 & \$ 50 \\\hline \text { Bird Watchers } & \$ 130 & \$ 25 \\\hline\end{array}$$ When Erie Textiles operates with a filter, the total gain (in thousands of dollars) by all three parties is ______.

A) $985
B) $600
C) $510
D) $475